Racism is increasingly recognised as a key contributor to poor mental health. However, the existing literature primarily focuses on its effects on adults.

To identify literature on the association between experiences of racism and mental health in children and young people in the UK.

Inclusion criteria were: (a) peer-reviewed publications containing original data; (b) UK-based research; (c) included examination of associations between mental health and experiences of direct or indirect racism (quantitative or qualitative); (d) inclusion of an assessment of mental health outcomes; (e) participant ages up to and including 18 years of age or (if the range went beyond 18) with a mean age of 17 years or less. Six databases were searched between 2000 and 2022; an initial 11 522 studies were identified with only eight meeting the inclusion criteria.

Five of the identified studies provided quantitative data and three provided qualitative data. The majority of studies (7/8) focused on children and young people aged 10 years and over; only one focused on children under the age of 10 years. Measurements of racism varied among the studies providing quantitative data. Only four studies directly focused on the effects of racism on the mental health of children and young people.

Although the included studies highlighted potential negative impacts of experiences of racism on children and young people in the UK, this review shows the lack of available literature to inform policy and practice. No studies examined the impact of internalised racism, systemic and institutional racism, or intersectionality.

Physical activities are widely implemented for non-pharmacological intervention to alleviate depressive symptoms. However, there is little evidence supporting their genotype-specific effectiveness in reducing the risk of self-harm in patients with depression.

To assess the associations between physical activity and self-harm behaviour and determine the recommended level of physical activity across the genotypes.

We developed the bidirectional analytical model to investigate the genotype-specific effectiveness on UK Biobank. After the genetic stratification of the depression phenotype cohort using hierarchical clustering, multivariable logistic regression models and Cox proportional hazards models were built to investigate the associations between physical activity and the risk of self-harm behaviour.

A total of 28 923 subjects with depression phenotypes were included in the study. In retrospective cohort analysis, the moderate and highly active groups were at lower risk of self-harm behaviour. In the followed prospective cohort analysis, light-intensity physical activity was associated with a lower risk of hospitalisations due to self-harm behaviour in one genetic cluster (adjusted hazard ratio, 0.28 [95% CI, 0.08–0.96]), which was distinguished by three genetic variants: rs1432639, rs4543289 and rs11209948. Compliance with the guideline-level moderate-to-vigorous physical activities was not significantly related to the risk of self-harm behaviour.

A genotype-specific dose of light-intensity physical activity reduces the risk of self-harm by around a fourth in depressive patients.